Ben Shelton gave a special shoutout to his soccer star girlfriend, Trinity Rodman, on Tuesday ... telling the world how much he loves her on her 23rd birthday.
The No 13-ranked tennis pro took to Instagram to deliver his romantic note ... saying, "Happy birthday beautiful girl. I love you."
Shelton published a pair of pics to go along with his mushy words -- a steamy shot of them moving in for a kiss, and another snap of the Washington Spirit forward's birthday dress.