Watching my girlfriend s sex video without masturbation , is a relapse ??

See you are not relapsing if you do not oose semen while watching the video. But if you feel that you have ejaculated then it's a problem, but it will draw your mind to porn again.
If you are on perfect semen retention that is not having sex or anyother thing that ooses semen, then you relapsed. But if you are just on nofap, that is not masturbating and not watching porn, then you are free to have sex, but don't masturbate even BY MISTAKE!
btw nightfalls are okay.
Dirty thoughts will come into your mind, but you have to counter them with good thoughts. For me, I listen sanskrit mantras to of lord shiva to control mind, you may have your own way.

 

Yup, that's also a relapse because she is masturbating and exciting YOU, the penis from where ejaculation is taking place is YOURS, so only coitus, nothing ELSE!