Why is the $C-O-H$ bond angle in alcohol slightly less than the tetrahedral angle,whereas the $C-O-C$ bond angle in ether is slightly greater?

The oxygen atom in both alcohol and ether is $sp^3$ hybridized.
In alcohols,the lone pair-lone pair repulsions are greater than the bond pair-bond pair repulsions,which pushes the bonding pairs closer together,resulting in a bond angle of $108.9^{\circ}$,which is slightly less than the regular tetrahedral angle of $109^{\circ} 28^{\prime}$.
In ethers,there is significant steric repulsion between the two bulky alkyl or aryl groups,which pushes the $C-O$ bonds apart,resulting in a bond angle of $111.7^{\circ}$,which is greater than $109^{\circ} 28^{\prime}$.