Thinking about trying it

My boyfriend wants to try anal and has been talking about it every now and then for a couple of months. I’m thinking about trying it but I might change my mind once I agree lol but like does the guy use a condom. When we have vaginal sex we use condoms but I’m worried that somehow some precum will leak to my vagina if he doesn’t wear a condom. Is it normal to wear one? I have no freaking idea