The invention relates to a cosmetic treatment process, in particular for caring for or making up keratin materials, comprising the following steps: a) a step of applying, to the keratin materials, a cosmetic composition comprising a compound comprising at least 2 maleimide groups； b) a step of applying a cosmetic composition comprising a compound comprising at least 2 furfuryl groups. The invention also relates to a kit comprising the two compositions, enabling said process to be carried out. The invention also relates to copolymers furfuryl (meth)acrylate, specifically (meth)acrylamide, and addition monomer chosen from polyethylene glycol (meth)acrylates and polydimethylsiloxanes with mono(meth)acryloyloxy end group.
