thats a heart line i think
The heart line, sometimes called the love line, is the line stretching across the hand directly under the fingers. The heart line reflects things related to the heart, like feelings, reactions, emotional control, etc. The longer and straighter it is the better.
If the heart line is short and straight, he/she has little interest in expressing love or romance.
If the heart line is long, he/she will probably be a good lover — sweet, understanding, and romantic.
If the heart line starts from the index finger, a happy love experience is predicted.
If it starts from the middle finger, it means the person usually thinks more of themself than their beloved.
If the heart line starts between middle finger and ring finger, he/she will easily fall in love.
If the heart line has a big rise and fall, he/she will probably fall in love with several people. Each love story will usually last short time.
If there are one or more circles on the heart line, the heart line is divided into several sections, or there are some short thin lines crossing the heart line, it usually means he/she is not very happy with his/her current love life.