I am glad you are young and have no kiddos yet..
Decisions may be a little bit less complicated without kiddos to think about..
Please heed my warning..I am just a couple of years shy of 60 and dealing with an un remorseful cheater who I am trying to get out of my life..
Whatever you do please don't marry this guy or become financially entangled with him..If you keep a relationship with him, maintain some distance legally (separate residences/finances)..
It sucks to be in such emotional turmoil within a relationship and feel trapped/unable to leave.... I'm not saying that you are in this situation, I am just warning you not to let the years slip by and find yourself in a complicated mess due to a spouse's infidelity..
There are people like me who have been married for 38 years or longer to un remorseful cheaters..It is hellishly complicated to extricate oneself from a long marriage and still have a financial future that looks intact..
I can't stress this enough... An important thing people have to think/plan for in the wake of their D days is to secure their finances..
Livelihood is a bottom line to survival and beginning a new life..
Working on one's emotional health is much harder when one has to work 80 hours in a week to survive, or when one is retired, disabled and praying that his or her lazy unemployed WH won't steal half of his her pension..
No matter what you decide for your future in life with this guy or other people, please take care of yourself first..Make sure you are independent and that no husband or boyfriend is financially dependent on you..
It is much easier to work on a relationship or say good bye to a relationship if one doesn't feel trapped..