In the current version, Skye hasn't mentioned any interest or lack of interest in sex, they just haven't mentioned it. Depending on what gender or genders Skye is attracted to, Mac and Lee would make the most sense.
If Skyee is only into other guys, We/MC shouldn't have any sex scenes with them. Because we are straight.
If Skyee is only into women, we do not qualify to have any sex scenes with them.
If Skyee is bisexual, into all genders, the most I think would work would be us having a threesome with them and a girl. This I feel would be very messy and would need to be written and handled very well. We can have MC open to penis play with his trans girlfriend, as we should, but despite all appearances Skyee is a guy, so anything we would potentially do to or with them is being done to a guy.
Giving head to Shauna is going down on a girl. Giving head to Skyee, is going down on a guy.
If we wouldn't go down on any other guy, we shouldn't go down on Skyee.