Lover (noun) "someone with whom one has a sexual relationship, especially illicit in character" When lover came into English in the 13th century, it developed several senses, but the illicit sexual sense appeared only 300 years later. Today, it has virtually taken over. So we have to be especially careful not to read it in when Shakespeare uses lover in the earlier sense of "companion, comrade, dear friend". This is the sense you need when Menenius refers to Coriolanus as "my lover" (Coriolanus, V.ii.14) or Ulysses says to Achilles:
"I as your lover speak" (Troilus and Cressida, III.iii.214). And in Julius Caesar remember to interpret the characters correctly when Artemidorus closes his letter to Caesar with the words, "Thy lover" (II.iii.8), Cassius refers to himself and Brutus as "Lovers in peace" (V.i.94), and Brutus harangues the crowd with "Romans, countrymen, and lovers, hear me for my cause" (III.ii.13). The plots could get very confusing, otherwise.
David Crystal is author, with Ben Crystal, of Shakespeare's Words, published by Penguin