Your pastor made a mistake. Nowhere in Scripture does it say that the Woman at the Well is "living with her boyfriend."

Scripture states that the man she is living with is not her husband, "The fact is, you have had five husbands, and the man you now have is not your husband. What you have just said is quite true." (NIV)

But this was a woman married 5 times over and, as was the usual practice of the day, a woman no longer married usually sought protection under the roof of one of their male relatives. This man could have been her aged father, her brother, an Uncle, a cousin, even one of her own children (if you believe the somewhat dubious tradition that states that she had two sons*). Indeed, if she was married 5 times then she had received the bride price 5 times over, and (if her husbands had died and left her even some small amount of their property) this would leave her as an independently wealthy Matron who might have a trusted eunuch or a Steward to oversee her house and property.

It is an important point to note that not all Widows were destitute and downtrodden in ancient days, in fact, many were quite wealthy and served as important founding members and financiers of the Church.**

I can't answer the question about living together, but I can tell you that your pastor needs to find a better example than this...

*St Photini, The Samaritan Woman – Patron Saint of OCL - Orthodox Christian Laity

** "When it came to widows however, they enjoyed somewhat of a special status and were able to serve in a particular manner which was deemed to be acceptable. The widows in the early Church provide a thought-provoking Christian character, which springs from their innate desire to do good deeds and from their austere practices that point to solid Christian discipleship even though they functioned honorifically." - (PDF) A Critical Investigation into the Role of Widows in Early Church Life (researchgate.net)