Seriously, it's one thing to be suspicious of someone when they are acting strange or out of the ordinary. It's another to be completely paranoid and untrustworthy of someone you claim to love and trust. If there is something that is bothering you, go straight to the source; don't rely on anyone else to get the truth. If the person denies anything, then you need to take their word; if it turns out that they continue to act strangely, then you might have some grounds to be suspicious.
On the flip side, someone who becomes suspicious of someone else(and completely out of the blue), it is often the case that the accuser might have something to hide, and their guilty conscious is causing them to lash out and seek faults in their significant other, in an attempt to justify their actions.
These are the type of people who need to grow up or be alone forever because they will never trust anyone and that paranoia will either drive their current partner away or cause them to cheat over nothing.
