A subatomic particle necessary for sexual attraction. Only applicable to anal encounters.
These particles have a half integer spin (and are therefore fermions) and have only been detected in high speed particle accelerators (like CERN) while technicians are participating in gay sex. There is not much known about these particles.
There may be some link between these particles and gravitrons.
Tutinos and two other fermions ofter combine to form various subatomic particles.
His silken buttocks radiate tutinos into my eyes....