I'm just wondering the best way to show telepathy between two beings in the company of non-telepathic beings. For instance there's a group of five, two girls have the gift. The three guys don't know two have the gift and there's a full conversation going on. Made up conversation: "So," said John, "Did you see the game?" "The ref needs glasses," said Mick, "How did he not see that foul?" Joe piped in, "It wasn't even a foul - the guy fell over his own shadow!" Now I need one telepathic girl to "speak" to her friend in secret, "What are these idiots talking about?" Do I need to spell it out? Mary looked at Rose, sent a thought into her head, "What are these idiots talking about?" "Who knows?" thought Rose, "Guys and their football huh..." I would imagine this would get repetitive and boring, would italics suffice? Is there another way?
Pretty much like you said, italics. Maybe: It would work better using a font with more obvious italics—some fonts italic letters really stand out. Like so: As long as you introduce your reader to this rule the first time someone speaks via telepathy it should fine. If you had to put in a 'Rose sent a thought into her mind' every time they spoke via telepathy, it would get old fast.
This has been asked and answered many times before. Do a forum search on telepathy. At the risk of stirring up someone's compulsion to argue whenever this comes up, italics are not the answer. Careful establishing of context is the answer, along with treating telepathy exact;y the same as any other form of literal communication, such as telephone, radio, or eyeblink codes.