If that's the only trait that's a bit too childish, I could deal with that. No big deal. If he goes to his mother's every day for lunch, has her doing his laundry and isn't capable of life on his own (provided he CAN live on his own), then that's weird for me. He could live at home and still do all of these things for himself. If he's not an independent man - ad least in the sense he's capable of taking care of himself - then that's a problem.
I wouldn't mind that much, but if it was my partner, we would have to have more that one TV in the house - you can be watching The Simpsons/Family Guy etc.. on one and I'll be watching The Walking Dead on the other, easy!