Such people generally regard showing off their girlfriends as a way to improve their external value.

It's as if he is an ordinary person, hoping to show off his girlfriend to improve others' views of himself.

However, this is not a very bad phenomenon, because everyone will have a show-off mentality.

This person should still love his girlfriend, but certainly not very deeply.

Because you love someone deeply, you will want to possess someone (maybe he wants to tell everyone that she is taken. Don't be partial, this is also a sign of love, see how you show off)