Intense, involuntary contractions of vaginal muscles that make intercourse painful for women are called:

Vaginismus.

Vaginismus is the involuntary movements that the vagina does, originated in muscle spasms. These movements may impede the woman from intercourse, any other type of penetration, or using any dispositive. The muscle that's the most directly involved with the spasms is the pubococcygeus muscle - but there are others that may be involved also such as the levator ani, the bulbocavernosus, the circumvaginal, and the perivaginal muscles.