Buddhist Tantra is not about coupling up with other people but training our own mind in deep meditation. This is particularly true for Gelugpas and Kadampas, including Je Tsongkhapa and Ven. Geshe Kelsang Gyatso, who emphasize strict celibate monastic discipline for those ordained as monks and nuns.
New Kadampa Tradition (NKT) practitioners are followers of Je Tsongkhapa, who taught that ordained Kadampas must maintain the outer example of the Pratimoksha vows, which includes refraining from all sexual activity. It is clear from all Geshe Kelsang’s Sutra and Tantra commentaries and teachings that sexual activity is not permissible for any ordained person under any circumstances. Geshe Kelsang himself never incurred even the slightest infraction of his celibate discipline.
The founder of the Gelugpa, Je Tsongkhapa, and all his followers and Geshe Kelsang categorically forbade any monastic from taking a Tantric consort at any point, even if they had high Tantric completion stage realizations. This is explained in the Tantric texts, including Clear Light of Bliss (which came out in the 1980s), when Geshe Kelsang says:
The highly realized Lama Je Tsongkhapa did not accept an action mudra because he was concerned for the welfare of his ordained followers … He wished to protect those impatient disciples of the future who, thinking they could follow his example without being fully qualified, would have been tempted to take a consort prematurely and thus would have created the cause for lower rebirth rather than for enlightenment.
In conclusion, there never has been and never will be any justification or excuse for any ordained NKT teacher or student to use Tantra as a pretext for sexual activity. Any such behavior will result in their being asked to leave their position and Center. Lay practitioners can learn the methods for transforming sexual activity into the path taught in the Tantric texts as long as they act in accordance with their Pratimoksha moral discipline of avoiding sexual misconduct.