"Is there something in this for me too?"
Possible responses:
1. Don't you know that even a "sow's ear has a silver lining"?
2. Do you always expect a "quid pro quo"? (latin)
3. Let's say there is, but only if you can guess what it is!
4. Did you ever think, it might be better to give than to get?
5. No, you should get pleasure out of doing just for me.
Let us hear outcome of this; you did not give us much in way of facts, ages, nature of friendship, genders, etc ... makes it hard to come up with best responses.
Rob