URGENT HELP- Boyfriend's co-worker and Victoria Secret

Thank you for reading this and for your quick responses.
I love my boyfriend more than anything.
I've never cheated on him, I would never cheat on him and he trusts me.
Today I was at the mall and had a coupon for Victoria's Secret.
I really needed a new bra and decided to go and use it, because it expired today and the store closed in 20 minutes.
On my way through the mall to the store, I ran into my ex boyfriend.
He and I are still friends, my boyfriend knows that and is OK with it.
Well, his current girlfriend got in a fight with him and left him stranded at the mall and he doesn't have a cell phone, so he asked if I could give him a ride home after I was done shopping.
I agreed and said I just wanted to go purchase something and then I would take him.
I went to VS and he followed me- but he walked behind me and we didn't talk. It was pretty obvious he was following me, though.
I text messaged and asked my boyfriend what color bra I should get (I'm terribly indecisive) and then went to check out.
That is when I ran into his co-worker friend.
We made eye contact, I know she recognized me, and then I left the line put my merchandise back and left.
I know she and my boyfriend are close- and I know I'll see her tomorrow at his Christmas party.

My boyfriend had been cheated on in the past and I told him I would never do that to him- and I wouldn't and haven't.
I guess I don't know what to do next- do I tell him what happened or wait to see if she says something

What would you do?

Tell your boyfriend what happened. It will be way better coming from you than someone else. Tell him asap. Then chill. You've done nothing wrong. You know it. That's what matters.

Of course you have to tell him what happened!! Jeez, if he found out from anyone else (especially since the chances are so high that he will) he'd wonder why you didn't!! Nip this potentially very messy situation in the butt. It also explains why you came home with no bra lol..

To be honest if someone else told me that first I'm going to wonder why it was worth hiding from me in the first place and probably would assume the worst an end it right there because my trust would be shattered and that's tough to overcome, if I was told by my gf I would still be pissed that he was there and would get into a fight with my gf but I would believe her story without reason to suspect anything else. Some guys might not jump to a conclusion like I would but it sounds like your decently young and I've noticed most guys my age range (23 for me) are very similar in this regard.

You made the situation worse by putting the bra back and running, that just screams guilty conscience!
You should have just carried on as normal, bought it, then told your boyfriend later the story of bumping into your ex and giving him a ride home.

Yes you should've just stayed in line and got the bra. You're not guilty of anything but I guess you just panicked. Tell your bf EVERYTHING. Explain it properly and I'm sure he'll understand. Small problem.

Thanks for your advice, everyone. I did end up telling my boyfriend and he was only upset that I let my coupon expire.
(Oh, the priorities in life)
I did panic because, well, I am normally pretty discrete when I purchase my underwear and the fact that there was a gigantic guy following me around the store didn't help.
I am so thankful for your help though- you really gave me courage and I can't express how appreciative I am of all of you.

Thank you so much!

Always tell your boyfriend something like this before he hears it from someone else. Otherwise you look guilty.

Why did your ex follow you into the store in the first place? Couldn't he have just waited outside until you were done? Maybe he actually wanted to see what kind of bra you were buying... meaning, maybe he still has a desire to hook up with you. And the fact that you let him come into the store with you (despite you saying you are pretty discrete when buying unmentionables) added in with the guilty conscience and flight response makes me wonder if there is something more here, something subconscious even. You say you would never cheat on your boyfriend, which is good, but maybe you were secretly hoping for a little attention from your ex? Not to act on, but just to enjoy the flirting and such? Just a thought...

But it is good you told your boyfriend about it. You need to feel comfortable communicating with him if your relationship is going to develop.

Good luck.

That is an excellent question. :)
My ex and I do theatre together on a regular basis, and so being in underwear is common place, with quick changes and all.
He and I were never physically intimate and he has since decided that he likes guys more than he likes girls- despite the fact that he currently has a girlfriend.
I guess that is why I didn't care that he was following me.
Your comment did make me think, though.
:)
Thank you all for your advice and feedback
:)

I would have fled the line too regardless of whether or not my ex was with me. I would have felt awkward by the idea that an acquaintance would be seeing my choice in underwear. If buying underwear online wasn't such a sizing risk I'd buy all my underwear on line.