The biggest factor here is whether you keep him happy in bed or not. If you keep him happy in bed, he will have no reason to look elsewhere. There are other factors, but this is a big one.
I think that for most men, sex is what creates an emotional bond to their mates. No sex=no bonding=no relationship. There are exceptions, but this is my theory. So for men, the sex is what creates the emotional bond. For women, the emotional bond usually comes first, then sex.
I have a long time interest in psychology, specializing in relationship dynamics for 30 years.
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