Jealousy over step son or innapropriate mother?

I need help discerning my issue..

I've tried posting this several times to no avail.. I think my wife behaves inappropriately but I also believe I am a little jealous and self conscious..

let me explain.. my step son came out of the bathroom in just boxers the other evening as I was going up the stairs and so I caught site of the size of his bulge and thought.. that's awkward.. he is larger than I am!! Then the other morning as I was exiting my room to go to the bathroom he had his door open and was naked in there and I caught a glimpse of him as he was walking about his room and again saw he was indeed bigger than I am in the male area.. now he quite often sits in his room in just boxers and so when his mother, my wife, goes in she must be able to notice this too.. now .. during the school holidays he has gone up to bed early saying goodnight around 8:30-9:00pm but then sits in his room on his phone snap chatting and on Skype etc. with friends.. this is ok.. as long as he is being sensible of course. Now despite the fact he has gone to bed early my wife still insists on disturbing him in his half naked state each and every night before we go to bed.. take last night for example.. he went up at 8:45 and we went up at 11pm.. now instead of just going to bed, as I did, she knocked on his door and went in, giggled over something I could not see or hear, but then informed him we were going to bed now and wished him good night, again.. before heading to the bathroom.. from bed I could hear him in his room doing his daily exercises.. sit ups, pull ups, push ups etc. and on the way back from the bathroom my wife, again, went in to his room in just her night shirt and him in just his tight boxers .. she told him how defined he was looking and how proud she was of his discipline hugged him, told him she loved him and came to bed, where she informed me, he is very defined and toned and how pleased she was he took the time to do his daily exercises..

I guess my point is, is this really appropriate regardless of whether they are mother and son.. he is after all 15 now and turning into a man.. clearly.. after all if a dad went into his 15 year old daughters room while she was in just a bra and panties and stood chatting with her while she went about her room in that state, told her how defined she looked and gave her a hug in that state of undress it would surely be considered weird and highly inappropriate, wouldn't it?

If you agree this would be inappropriate should I then mention how I think it is inappropriate for her to be in her sons room in his state of undress or am I being oversensitive ..