How would you feel in this situation ?

Bl

Today is my boyfriends birthday. We have been together for 4 years. He told me that some co-workers gave him a birthday card and I thought that was sweet. But when he brought it home and showed it to me, 4 women wrote on there calling him “cute” and saying that they “love” him. I thought that was strange and asked him about the women. He said its nothing but I thought was weird. How would you feel? I just feel uncomfortable about it.