bf giving repetitive quick glances at another girl in front of me

we were at disneyland and waiting in line for a ride for an hour. there was a girl who had a nice body wearing skin tight exercise clothing in front of us. my boyfriend kept making multiple, repetitive quick glances at the girl's body and even the girl would look back at him a couple of times.

I felt so uncomfortable so I stopped holding his hand or giving him affection unless he initiated it. instead, he ended up holding me around the waist closely to him.

not sure what was happening here, but all I know is that his actions made me feel inadequate and so I almost wanted to bring it up but ended up not.

do you think something is fishy here or am I overreacting? should I bring this up to him?