Um. I have huge trouble refusing gifts because it is so ingrained in me that gifts are to be accepted and thanked for. But I agree, in this setting it is manipulative. He may not consciously know that that is what he's doing, but he is somehow trying to make you "soften up". If you want to be gentle, you could choose one gift, for example the collage, and say you'd like to keep it because it was thoughtful and reminds you of the good times you had (or whatever). But the others - if you can bear it - return them, just saying that you can't accept them because you are no longer a couple and it feels wrong to you. Don't go on about how wrong he is, stick to expressing your own feelings. Dare to be the "bad guy". Someone has to, in a break-up.
Winter riding is much less about badassery and much more about bundle-uppery. - malkin
1995 Kona Cinder Cone commuterFrankenbike/Selle Italia SLR Lady Gel Flow
2008 white Nakamura Summit Custom mtb/Terry Falcon X
2000 Schwinn Fastback Comp road bike/Specialized Jett