Redditgifts is family friendly. As a Santa, you should not be sending NSFW (Not Safe For Work) items unprompted, even if your giftee participates in NSFW subreddits. If your giftee has indicated that NSFW items are something that they would be OK with, that is different and you may send NSFW stuff in that instance if you, the Santa, are comfortable with it. You are not required to send your giftee anything in particular, regardless of what they have put in their preferences. Generally, it is best to not send NSFW items and to keep things family friendly and PG-13 at most.