[bamasconfusedgf]

OK hello out there I will try to keep it short.
I have been dating a guy for 3.5 years, we are both 26 and have been living together almost 3 yrs. We had a small argument about him going out after work and not giving me a heads up not to wait up. He stayed out till 3 am and i told him how mean it was for me to be up worried while his phone was dead and he was out drinking. We didnt talk much the next day till I finally broke and said I was sorry and he said he was sorry for not shooting me that 5 sec text saying he was going out.
Well a few days later I was digging in his phone for a mutual friends email address. I saw that the day we werent talking he made an online dating profile and messaged over a dozen women asking if they wanted to "hook up". Even telling some he didnt have time to date bc he has a gf.
Weve been in a similar place before and I love him very much and I know he loves me. I dont know why hes cheating/ tryng to cheat. We talk about marriage and kids and buying a house together, so I feel like he does want a future together.
I dont know what to do! Do I continue and ask him to go to couples counseling or do I throw away a sweet, understanding, smart guy?

A little back story:
We broke up for a month at about the 18 month mark and he slept with a few girls and even taped one session. I saw this video and then kinda understood a different side of him. Im a cute girl i guess small size and that is what 90 % of his exes were also. But the girl in the video was not his type at all she was like the women he messaged online (a week ago). She was on the larger side and not cute. He was saying things to her in video that were almost mean (not about her looks). It was like he had to choose a girl with low self esteem who would allow him to be a jerk.