You just remembered that there is a group assignment and you have to visit one of the group members to work together at his house. and coincidentally the person you visited was a male member.

Then when you want to leave, u tell your boyfriend that you have group assignments. then your boyfriend chats with you

"Are there any guys in your group? Are you visited a guy's house? If so, I have to come with you." he said that with cold tone and he so jealous