I don't always see strength...it definitely would have to combined with another card or two, as well. It could mean that there is nothing there, that you just need to "be strong" and move on from the situation...it really depends!
There are sooooo many cards that can represent flirting, however remember they must always work with the rest of the spread and have supporting cards. I feel that no one card can "rest on its own" for situations that are complex, such as relationships, where TWO people are involved!
Just some cards to watch out for and see how they interact with other cards (no particular order):
The Lovers, Two of Cups, Six of Cups, Page of Cups, Nine of Cups, Ace of Wands, Ace of Cups, Ace of Pentacles (When it was all just about a physical relationship), Ace of Swords (using words to flirt...quips...etc, but this MUST be combined with another supporting card that you would know when you saw it.
And then so many wands...as I said, the Ace...then the of 3 of wands "putting something out and seeing if it is returned to you". Heck, I have even seen "5 of wands" before. In a relationship spread, I once pulled this for what someone is usually attracted to and I was like "competition; the chase!" Then of course the Queen of Wands, King of Wands, even pages and knights...I don't really see Queen/Kings of Cups unless something has really developed. Also, King/Queen of Pents could be someone who is just really looking for a physical "material" relationship.
For "inaccessibility" I have seen four of pentacles before. Of course this needs to be with other supporting cards, otherwise it can show that there just isn't anything there.
Hope this helps...again it really is just hard to say; just one of those things that you will know when you see it in a spread. At the end of the day, intuition is key, combined with what you've objectively witnessed happening between you and the other person. <3