How do I get my 3 year old son to give affection to his little brother?

So I have a 11 month old baby that I still breast-feed and I have a 3 year old, so there’s times they play together and my little 11-month-old loves him so much he’s always trying to give him affection and always tries to kiss him and just lay with him but my 3 year old doesn’t like it, he does not want to give him any type of affection and tries to push him away when he does, he plays with him but won’t give him love and it’s frustrating to see that because I want them to have a loving brother relationship.

My question is how do I get him to give him love? how do I have him get close with him? Everytime I tell him to give him a hug I see it in his face he doesn’t want to and doesn’t like doing it. It honestly makes me feel horrible because all I want is my boys to have a good relationship