Father’s Day gift from step-son HELP!?

Hi ladies, so I’ve been with my boyfriend for a while and we have his 4 year old step son 4 days a week and me and his son are super close!

My boyfriend is an incredible dad and I want to buy him something from his kid just to say thank you.

Obviously his ex buys him Father’s Day gifts too but is it weird for me to do it too??

I was just thinking a gift like a photo of my bf and his son in a nice frame?

Please help xx