SkyWhile
Moon is VOC (no where further to go in this situation) in the higher sign Sagittarius brought down low into the 3rd house intercepted-situations will be held at bay (suspicions, don't make a mountain out of a mole hiill) so don't think too much about conversations you overhear, Moon so close to the 4th house of ending conclusions, doesn't take energies (Moon in the house of conversations Mercury) any further.
I don't use the boyfriend house as the 7th, although it pertains to all things of a partnering. I am using the 5th (potential romance evolving into partnership 7th) house for the boyfriend whom is ruled of Saturn and Uranus. Five houses (his romantic interest) from that house is the 9th which is ruled of Venus (Pliades on the cusp-the weeping sisters) and Mars in talkative Gemini, as attractive energies. She is ruled of the 9th house lords, her depositor is Jupiter/Neptune, ruling the sign Sagittarius/Pisces and Mercury whom in the natural radix rules the 6th house. He would rather you not hear the telepone calls as he wishes to keep them to himself, 6th house is cadent and hidden. Sagittarius intercepted in the 3rd is; you don't hear what you should be hearing to make a more qualified judgment. Jupiter is between Saturn and Mercury, Mercury is moving 'away' from your Saturn.
Venus is hiding behind him (Venus is Combust the Sun), Saul whom rules the 5th house naturally and whom is additionally hiding in his 6th house of habits, (trying to hide his actions in this scenario, are you a jealose type), he see's a mild-interest not necessarily an (Venus Combust Sun) attraction in her because of her frailty, but as yet there is only conversation.
My thought is she is siddling up to him, (Venus is faster than the Sun) not the other way around for some reason other than romance, she is looking for protection or a listening ear to hear her plight? Put the ball in his court to be reassured and you will have the right answer if you ask, wistfully-not to ruffel his feathers?
Am only a neophyte in Horary, but I don't think you have anything to worry about.
StarDust1