I got my lippierced about a month ago I started making out with my boyfriend recently and it has been hurting to move it is it because I have been makeinout with him or something else

It's probably from the kissing but it could be infected so it's best to let your doctor take a look at it. It usually takes lip piercings about 2 to 3 months to heal so kissing right now is probably not the best thing to do since it's only been a month. Follow these steps to prevent infection:

Wash your hands first with soap and water before touching or cleaning the pierced area. (Don't let anyone else touch the pierced area until it is healed.)
Remove any crusty material from the site and from the jewelry with warm water.
Gently wash the area around the piercing with antibacterial soap (liquid soap works the best).
Gently rinse off all of the soap and crusty discharge.
Gently dry the area with a paper towel or plain white napkin. (Bacteria can stay in cloth towels.)
Do steps 1-5 twice a day until the skin heals. (Over-washing or over-scrubbing can irritate the area.)
Do NOT use antibacterial ointments because they don't allow air to get to the area and they trap bacteria.

Those steps are from: Body Piercing: A Guide for Teens (http://www.youngwomenshealth.org/body-piercing.html)

I agree with rank, the irritation is more than likely caused by kissing. Remember that your piercing, until it heals, is an open wound. You want to be careful when introducing other people's bodily fluids (including saliva) to your piercing. I know it may be hard, but you should stay away from making out until you give your piercing a chance to heal. I don't mean heal all the way, I mean give it a chance to heal from this particular irritation. Also, as rank said, make sure you clean your piercing. The only thing I would add is to reduce cleaning to once a day. It is a month old, and now you want to concentrate on healing. Too much cleaning can prolong healing time, because every time you clean it you interrupt that healing process.

Also, be careful with makeup. Makeup can also irritate piercings. If you need to use it, I would suggest not putting any directly on the piercing. Leave a tiny space around it. Makeup can also cause irritation, and irritation can lead to infection and unattractive scarring. :)