Can I ever make him forget?

He won't forget it, never, just as you will never forget many things in your past. Show him all your love and acceptance and get married to him, otherwise you should never have slept with him in the first place. Did sleeping with him mean anything to you? If it does then you should understand and not complain.

Sounds like this guy is trying to put something on you because he feels guilty about something that he has done. What that is, not sure,... but there is something up with him that he is trying to project onto you.

Tell him about couples in their thirties and forties who know what they want and sleep with each other right away and have great relationships.

You are only sleeping with him (right?) and only him and that's all that matters. You treat him good, are loyal. (I hope :)
He slept with other women in the past and maybe has slept with women the first night he met them. THAT IS IN THE PAST. All that matters is your relationship and being loyal and fatithful to each other NOW. If you only sleep with him you are not a slut. It is not important and you guys should focus on the present and the future. Everything else is insecurity.

Yeah true. Why is he still into you if he's asking those questions? What does he want you to say? I guess he's trying to make you feel like a slut(?) is that who you want to be with?

Tell him to get over it!! And if he keeps bringing it up then you both just are gonna have to part. Believe me if he really can't let it go he never will and he will keep bringing up things you do and throwing them in your face your whole relationship...I know...that is how my ex-husband was...I just got sick of it and left him.

You know having sex is a decision between two people, not one. There is no time frame on when to have sex. If the feeling is mutual great. Be assertive, you should not be with someone who doesn't think highly of you. what a jerk!

I think that it is his problem if he felt the second time you saw each other was too soon then he could have said no. It takes two... What you are telling us is that you think that he thinks you are a slut. You don't have to take that from anyone.