Most Helpful Guy
He's playing with your feelings (and body meanwhile) until someone else comes along. He's acting cute to persuade you into sex, while maybe feeling a bit sentimental about your past. Don't misread this, he's using you. If you want, use him as well but be careful.
Most Helpful Girl
There's 3 options.
1) You guys did date before... he may still have lingering feelings but is unsure.
2) It could also be that he misses you and wants you back
3) Wants you to be his youknowwhat buddy.-.