My son is a very sweet boy. He's already 10 years old but he still hug and kiss me in front of other people. Although that's not always the case, I just succeeded, I guess, in
brainwashing explaining why he shouldn't be ashamed of being sweet to his family.
I remember when he was 4 years old, we just arrived in his school and I waited for the see-you-later-kiss. But he went straight to his classroom. I caught him just in time, before he opened the door, and I asked for a hug and a kiss. He did hug and kiss me but with an averted gaze.
I talked to him after school, he's getting conscious, he doesn't want his classmates to tease him. "Are you a Mama's boy?", I asked him. He said "Yes", maybe because he doesn't want to hurt my feelings.
"Being labeled a Mama's boy and showing your affection to people you love is not something you should be ashamed of. You should be proud that Mama loves you and that you also love Mama very much. If someone teases you again, just ignore them."
I'm hopeful that he'll forever be a sweet boy.