In this Parsha it is difficult to determine Yaakov's true feelings towards Leah. After having been tricked into marrying Leah, Yaakov then marries Rachel after committing to seven more years of labor for Lavan. The Torah tells us that Yaakov "...consorted also with Rachel and loved Rachel even more than Leah." The Torah seems to be telling us that although he loved Leah, he loved Rachel even more. The problem is that the Torah then tells us immediately that "G-d saw that Leah was hated, so he opened her womb." After Leah gives birth to her first-born, she says, "Because G-d has discerned my humiliation, now my husband will love me." Then, after giving birth to her second son, she says, "Because G-d has heard that I am hated, He has given me this one also."
From the last three quotations it appears that Leah was hated by Yaakov, while the first quotation seems to indicate that she was certainly loved, just to a lesser degree than Rachel. Abarbanel explains that there is actually no inconsistency. The first verse is not an indication that Yaakov loved Leah. (Perhaps, as Ramban explains, Yaakov had consistently negative feelings toward Leah as a result of her having deceived him on his first wedding night.)
Abarbanel offers a grammatical explanation of the first verse quoted. The literal translation of that verse is Yaakov "consorted also with Rachel and loved Rachel from Leah." The Hebrew letter 'mem' which literally means 'from' can also mean 'because of'. Now the verse translates as he "...loved Rachel because of Leah." He explains that because of Yaakov's total inexperience with women, his desire for a particular woman, i.e. Rachel, was intermingled with his basic desire for any woman. Therefore, when he had relations first with Leah, this aspect of his physical desire should have been satisfied and his ardor for Rachel should have cooled somewhat. However, the opposite occurred. After marrying Leah, rather than having his connection to Rachel diminished, it was actually augmented. He now realized that his feelings toward Rachel went far beyond simple physical desire, as that aspect had already been experienced. Thus, because of his experience first with Leah he experienced a deeper and more authentic love for Rachel. Furthermore, having been with Leah, his love for Rachel took on a second dimension. His initial love for Rachel was for who she was, independent of others. But now he could compare her to Leah and see even more clearly how she completely fulfilled his purpose in life. Again, it was because of Leah that Yaakov's love for Rachel deepened.