Romeo Bio
After being recruited by Echo after Echo's first partner, X-ray, sacrificed himself during a mission, the pair were inadvertently separated during the course of a mission. Romeo was injured, and the ER doctor of record was later recruited herself and became Agent India. Some adventures apparently ensued during Romeo's treatment -- possibly including an attack on the ER, which the physician put down with martial arts skills and whatever medical equipment came to hand -- and the two became emotionally attached. Once Echo located his partner, however, the woman who became India was duly brain-bleached, and Romeo moved on.
However, when he severely broke his leg in a gym accident, he discovered that she had been recruited to the medlab, and they rekindled their relationship after Fox gave permission to download her memories of the incident. Echo stepped aside for the relationship, and Romeo and India became partners and lovers. After Alpha One became the first successful partnership in the new Alpha Line department, Echo put Romeo and India through testing, and they were inaugurated as Alpha Two. They became engaged the following Christmas.
As of the events of Break, Break, Houston, they are officially married as well.