It depends on a few different variables. Not all men know how to control ejaculations during sex. Some men ejaculate quickly because they are very excited or attracted to the person they're having sex with. It can be easier to keep an erection longer and not ejaculate quickly with someone they are not as attracted to or in love with.
On the other hand, if has previously been able to control it but now goes quickly there are 2 possibilities: 1) he's not trying as hard to last longer, or 2) he's aging. Another clue would be how long ago the affair was.
Let me know if you need more help.
Is there a possibility that quick ejaculations occur due to other reasons other than being really attracted, excited, or in love with than person, but simply the fact that they are stressed or lack of self-confidence due to the quick ejaculation and the actual thought at the time of being afraid to ejaculate to quickly? And maybe with this other woman he could have been relaxed or better sexual chemistry??? He had this affair only 3 weeks ago. But this situation between us has been going on as long as our marriage of 10 years, maybe 2 or 3 times he has been able to last longer long ago, but yes things became worse since the affair began.
Does quick ejaculation make a bad sexual chemistry, does it mean we are not compatible in bed??/
Sorry for the delayed response. You are correct...stress & lack of self-confidence also can lead to premature ejaculation as well as performance anxiety. Sexual chemistry is not a black or white thing. There are various degrees. Perhaps your current chemistry isn't as good as it used to be...and it seems that is likely related to the affair. I wouldn't jump to the conclusion that he has better chemistry with the other women.
Perhaps he was excited by this affair and being "bad" that he lasted longer with her. Real sexual chemistry is based on an emotional & spiritual connection. And it's something that can be worked on. There are may books written for couples having relationship or sexual difficulties. You may also want to consider a couples therapist...perhaps one with expertise in sex therapy too.
The affair is a symptom of some emotional distress in the relationship and is something that definitely needs to be addressed and worked on. I hope this helps clarify. Anything else I can answer for you?
Good luck & take care.