HERPES😭😭

So i gave my bf a blowjob the other day when i had like the first day of a coldsore I didn’t realize it was one but then He said nothing is changing but i guess he has this little rash on his penis but not blistery or itchy or hurting. dosent hurt when he pees he dosent want to go get tested because his mom would flip but he says he dosent have anything like he’s fine but idk i feel like maybe he has it. what should i do? is there any home testing things i can do to find out if he has it?